Evaluation of the mechanical properties of fully integrated 3D printed polymeric sandwich structures with auxetic cores: experimental and numerical assessment

Selection of appropriate topology to use in the core of the sandwich structures is one of the serious challenges ahead to design of them. This study aims to investigate the influence of auxetic core topologies on the mechanical characteristics of fully integrated 3D printed polymeric sandwich structures. Specifically, three types of auxetic cores including square node anti-tetra chiral, re-entrant, and arrowhead were investigated and compared with the conventional honeycomb in terms of energy absorption, compressive strength, and Young’s modulus. The specimens were fabricated using FDM 3D printing method and quasi-static compression and low velocity impact loading tests were performed on the printed specimens. Moreover, finite element simulations were conducted to compare with experimental results and deformation patterns as well as for parametric study. Results indicate that the core topology is a critical parameter impressing the mechanical properties of sandwich structures, and using the auxetic cores improved the desirable properties of sandwich structures in both types of loading. Auxetic cores cause the sandwich structure to have more resistance to imported compression, while conventional honeycomb doesn’t have this superiority.